1. In the mouth and stomach,salivary -amylase initiatesthe digestion of which nutrients? A. Proteins B. Carbohydrates C. Fats D. Fiber: Answer B Salivary -amylase is an enzyme that initiates only carbohydrate digestion in the mouth and stomach. 2. Which elements in saliva protect against tooth decay? A. Salivary -amylase and ptyalin B. Secretin and IgA C. Endogenous enamelin and salivary -amylase D. Exogenous fluoride and a pH of 7.4: Answer D The bicarbonate concentration of saliva sustains a pH of approximately 7.4, which neutralizes bacterial acids and prevents tooth decay. Exogenous fluoride (e.g., fluoride in drinking water) is absorbed and then secreted in the saliva, providing additional protection against tooth decay. 3. Saliva contains which immunoglobulin (Ig)? A. IgA B. IgE C. IgG D. IgM: Answer A Saliva contains only IgA, which helps prevent infection. 4. What effect is a result of inhibiting the parasympathetic nervous system with a drug such as